Wood strip floor structure



2 Sheets-Sheet 1 N. G. HUNDLEY WOOD STRIP FLOOR STRUCTURE March 27, 1962 Filed May 27, 1958 N. G. HUNDLEY WOOD STRIP FLOOR STRUCTURE 2 Sheets-Sheet 2 IN VENTOR /Vo/'vele G, Handley Mam @mk/0M ATTORNEYS March 27, 1962 Filed May 27, 1958 United States Patent O 3,026,578 WOGD STRIP FLOOR STRUCTURE Norvelle G. Handley, Kenova, W. Va., assignor, by

mesne assignments, to Horner Flooring Company, Dollar, Mich., a corporation of Michigan Filed May 27, 1958, Ser. No. 738,233 1 Claim. (Cl. 20-8) This invention relates generally to a Wood strip oor structure and more specically is directed to a sectionalized strip ooring construction wherein conventional tongue and groove long strip flooring is assembled into sections for incorporation in a floor covering.

Heretofore there have been many proposals for wood floor construction having particular utility or application to flooring large areas, such as gymnasiums, anditoriums, etc. Standard strip oor construction for these applications usually involves nailing the individual flooring strips to nominal 1 inch thick subflooring wherein such subflooring is elevated above a concrete slab by nominal 2 inch thick screeds spaced 16 inches on center. These screeds are attached to the concrete slab by the use of specially designed clips, concrete nails, screw fasteners or by asphalt mastics. Under this procedure all of the wood components within the floor are secured by nailing.

This standard type of strip flooring has proved through long usage to be very serviceable and when properly installed provides a highly durable and stable floor. Expansion and consequent possible buckling is effectively restrained by the individual nailing of the flooring strips.l Such standard strip flooring is considered to be one of the most attractive and desirable floors from the architects and users viewpoint, and with proper finish and maintenance procedures, will retain thisl appearance over long periods. Y

The chief disadvantages of such standard strip ooring procedure are that relatively skilled labor is required for installation in order to properly space butt joints between the flooring strips, etc., long downtime is required toV install this type of iloor, variation exists in the firmness of the floor between areas directly over screeds and areas between the screeds and, particularly due to increasing labor costs, the installation cost of this type of oor is relatively high.

A modied design of this standardwood strip flooring technique uses relatively short strip lengths applied directly to a concrete slab by use of coal tar pitch or asphalt mastics. This design is generally referred to as mastic set flooring. Its advantages are that it is relatively simple to install, requires a short downtime for installation, has uniform firmness to be well suited for industrial applications where heavy loading is expected, as compared with standard strip flooring installed on screeds and subllooring, and due to its simplicity and ease of installation, the overall installation cost of mastic set ooring is less than for standard strip flooring.

However, mastic set -oors are highly susceptible to buckling due to expansion. The mastics used to apply such oors to concrete generally provide relatively -high tensile strength, but are low in shear strength. As a result, expansion is not restrained as it is on standard strip `flooring in which the individual strips are nailed.

A third major type of flooring particularly employed in gymnasiums and large areas where a wood oor construction is desired is termed a floating floor. In this type of floor wood strip flooring is nailed to heavy plank subilooring having a nominal thickness of from 11A to 2 inches and 4 to 6 inches in width. The sub-ooring is spaced 1/2 inch apart and is set in mastic on the concrete base. An installed lloating oor resembles standard strip ooring construction except that the heavy subooring 3,026,578 Patented Mar'. 27, 1962 ice replaces the screeds spaced 16 inches on center and the normal l inch subooring.

The advantages of a oating oor are that the appearance is similar to conventional strip flooring construction and consequently satisies the existing preference among architects and users. Due to lower labor costs to install plank subilooring in mastic, the overall cost is less than in conventional strip llooring. The disadvantages of a floating floor are that relatively skilled labor is required in order to properly space the butt joints, etc., as in the case of standard strip flooring construction, long downtime is required to install the floor and the oating iioor has a greater tendency to buckle by expansion, since the subooring planks are not attached to the concrete except by mastic.

Considering the advantages and disadvantages of the above discussed prior flooring proposals, along with several less common types of flooring construction, the flooring system of the instant invention has been developed to embody long strip wood flooring into a oor structure to satisfy the appearance preferences of architects and users developed through long usage of and experience with standard strip flooring construction.

Additionally, the floor system of this invention enables application of conventional tongue and groove strip iiooring direct to concrete to have the advantages of uniform lirrnness and adaptability to both gymnasium and industrial applications. In carrying out the invention, preassembly of standard strips into larger and more uniform length ydimensions has been employed. T-he system maintains the desirable stability properties in respect to both low expansion and uniform shrinkage characteristics of conventional tongue and groove strip ooring installed on subilooring. Finally, the floor systemallows for speed and ease of installation in order to reduce installation downtime and installation costs. v

Thus, the instant invention has been developed to utilize conventional tongue and groove strip ooring, with a plurality of flooring strips assembled into a flooring section with the mating tongues and grooves interengagedand screeds adhesively secured to the underside of the strips to extend transversely thereof at spaced positionsl along'the length of the strips. A particular interrelationship of the end configuration of the screeds and their relationship to the flooring sections is embodied in the invention to facilitate assembly of the sections and insure requisite floor firmness at all points. The screeds also provide means for attachment of the sections to the supporting base such as a concrete slab.

It is a principal object of this invention to provide an improved sectionalized flooring structure utilizing conventional tongue and groove wood strip flooring fabricated into sections with the ooring strips interconnected by transverse screeds and filler strips disposed between the screeds, and wherein mastic is employed, to retain them positioned between the ooring strips and supporting base for the structure.

Another object of the invention is to provide a floor section for incorporation in a sectionalized flooring structure wherein tongue and groove flooring strips are retained in interengaged relationship by transverse screeds adhesively secured to the underside of such strips at spaced positions along the length of the strips.

itis a further important object of this invention to provide an improved sectionalized flooring structure in-v cluding tongue and groove Flooring strips retained in interengaged relationship by transverse screeds wherein the individual screeds have the ends thereof formed to provide an interlocking relationship between the screeds and the edge ooring strips of adjacent sections thereby to facilitate attachment of the sections to a supporting base such as a concrete slab.

The above and other more specific objects and features of the invention will be more apparent by reference to the -description given hereinafter in conjunction with a specific embodiment of the invention shown on the drawings, in which:

FIGURE l is a plan view showing a plurality of flooring sections assembled in accordance with the instant invention;

FIGURE 2 is a bottom plan view of two flooring sections showing the relationship of the interengaging screeds;

FIGURE 3 is a sectional view taken on line 3 3 of FIGURE l; and

FIGURE 4 is a sectional view taken on line 4--4 of FIGURE 1.

Referring to FIGURE l, there is shown mounted on a suitable supporting base, such as a concrete slab 10, a plurality of flooring sections. The end joints between longitudinally aligned ooring sections are staggered across the width of the surface of the supporting base to which wood flooring is to be applied. This staggered relationship is achieved by employing two standardized section lengths. As shown, the flooring sections 11 are of a length equal to twice the length of flooring sections 12. For example, the sections 11 are preferably eight feet in length, Whereas the sections 12 have a four foot length. The particular screeds employed on the respective sections 11 and 12 are of a unique configuration and are different for the two sized sections to achieve proper interengagement, as will be described in detail hereinafter.

Each of the flooring sections 11 and 12 is made up of a series of flooring strips. These strips are of the conventional tongue and groove variety as now extensively used in conventional nish wood flooring. In other words, each strip has a tongue extending longitudinally along one edge thereof and a complementary groove extending along the opposite edge of the strip. The series of strips have the adjoining tongues and grooves thereof interengaged to form the ooring section.

The strips employed in fabricating a particular section may be of random length with butted tongue and groove end joints being provided at the junctions formed within the surface of a particular section. Preferably in fabricating the sections the outermost flooring strips along opposite sides of the section shall be maximum length, i.e., corresponding to the length of the particular section in which they are assembled. By Way of example, the flooring sections may be assembled from four conventional 25/32" x 2%" tongue groove flooring strips to provide a section width of 9 inches.

The ends of the flooring sections are cut off perpendicular to the longitudinal length and the ends of the ooring strips levelled for better joining of the section ends.

To insure that expansion and contraction of the ooring strips within a section may take place due to changes in moisture conditions to which the flooring section is subjected, it is particularly important that no bonding of the interengaged tongues and grooves between the strips be employed. Thus, the individual strips within a section are free to separately expand and contract. The screeds described hereinafter are secured to the underside of the flooring strips at spaced transverse positions along the length of the individual section.

FIGURE l shows the interengaged relationship of the ends of the screeds at the adjacent sides of adjoining sections. FIGURE 2 illustrates the particular configuration of the individual screeds and their relationship to a flooring section 11 and a flooring section 12.

The outer dimensions of the iioor surface formed by the strips in the sections 11 and 12 are shown in phantom o n FIGURE 2. It will be noted that each screed in both of the section sizes shown has end portions thereof projecting outwardly beyond the sides of the section. In other words, each screed in a section extends beyond the groove or tongue of the sidemost flooring strip in such section. As shown more clearly in FIG- URE 1, by such a relationship, the outwardly projecting end portions of the screeds engage beneath the sidemost flooring strip of the adjoining section in assembly of a plurality of sections into a complete flooring structure.

Referring more specifically to the configuration of the individual screeds, section 11 is provided with an end screed 15 having a uniform width throughout its length. This end screed is secured transversely of the underside of the ooring strips which form the oor surface of section 11, with the ends of the strips of such section extending a predetermined distance beyond the outer edge 16 of screed 15. Thus, the outer edge 16 is rccessed this predetermined distance inwardly from the ends of the strips forming the oor surface of section 11.

The opposite end of section 11 is provided with an end screed 18 secured transversely of the flooring strips forming the section. End screed 18 is secured to the underside of the flooring strips forming section 11, with the outer edge 19 thereof disposed a predetermined distance beyond the ends of such strips. In other words, a portion of screed 18 is not covered by the ends of the ooring strips which make up the section. This uncovered portion has a width substantially equal to the recessed distance at which outer edge 16 of screed 15 lies inwardly of the ends of the flooring strips at the opposite end of section 11.

Screed 18 is provided with a notch 20 at one end thereof and a notch 21 at the opposite end thereof. These two notches are provided at diametrically opposite corners 0f the screed 18 so as to provide a step portion along one edge of the screed at one end thereof and a step portion along the opposite edge of the screed at the opposite end thereof.

A plurality of intermediate screeds 25 are provided extending transversely of the flooring strips at spaced positions between the end screeds 15 and 18. As in the case of the end screeds, the intermediate screeds have end portions thereof extending outwardly beyond the edges of the flooring strips along the opposite sides of the section. Each intermediate screed 25 has a notch 26 at one end thereof along one edge of the screed and a similar notch 27 at the opposite end of the screed and yalong the opposite edge of such screed. The notches 26 and 27 on the intermediate screeds 25 provide step portions at diametrically opposite ends and along diametrically opposite edges of the screed. Each step portion is-disposed beneath the ooring strips which form the door surface at, the sides of the section. It will be noted that the notches 26 and 27 extend inwardly from the edges of the screed to the longitudinal center line of the screed.

Flooring section 12, which, as noted hereinabove, is of a length equal to half the length of flooring section 1l, is provided with screeds as discussed hereinabove with reference to flooring section 11. Thus, flooring section 12 has end screeds 15 and 18 with the outwardly facing edges 16 and 19 thereof disposed, relative to the ends of the ooring strips which make up section 12, similarly to the relationship of the end screeds on ooring section 11. A plurality of intermediate screeds 25 are provided at spaced positions between end screeds 15 and 18.

Flooring section 11 has, in addition to end screeds 15 and 18 and intermediate screeds 25, a center screed 39. This screed has end portions projecting outwardly be yond the sides of the section and has a deep notch 31 at one end thereof. The opposite end of the center screed 30 is provided with notches 32. and 33 along opposite edges to provide step portions along both edges at this end of the screed.

As will be apparent lfrom FIGURE 1, the configuration of the screeds and their relationship to the ooring strips which make up the surface of a section is important to provide interlocking between the screed ends and adjoining sections in assembly of a plurality of sections into a flooring structure. As so assembled, the individual screeds provide continuous width supporting members across the width of the supporting base at a plurality of parallel positions transversely of the flooring sections assembled into the floor structure.

By way of example, and adopting x as a constant factor, the various screeds and notches formed -at the ends thereof under the teaching of the instant invention may have the following relationship. Assuming a width for end screed 1S of 4x, the outer edge of such screed will be positioned to leave a distance equal to 3x between the ends of the flooring strips for the particular section and such outer edge. The end screed 18 will have a width of x with the outer edge 19 disposed a distance equal to 3x beyond the ends of the flooring strips making up the section. The notch 20 will extend a depth of 6x inwardly from outer `edge 19 and the notch 21 extend a depth of 4x inwardly from the opposite edge of the screed.

Under the assumed example, the flooring section 12 will have two intermediate screeds 25 located at substantially one-third and two-thirds respectively of the length of the section. Section 11 will have intermediate screeds 25 located appropriate distances from the end of such section to interengage with the outwardly projecting end portions of the screeds 25 on section 12. This relationship is clearly shown in FIGURE 2. The intermediate screeds 25 will have a width equal to 14x with each of the notches 26 and 27 having a depth of 7x.

The center screed 30 will be provided midway of the length of section 11 and have a width of 14x. The notch 31 will have a depth of 10x and each of the notches 32 and 33 have a depth of 4x.

With the hereinabove described relationship of the screed widths and notches widths and their positioning on the underside of the strips forming the flooring sections, it will be appreciated that a flooring structure embodying the Iinstant invention will have screeds extending continuously and transversely of the strip flooring with the screeds having a uniform width of 14x. Each screed on a particular section will have end portions thereof engaged 'beneath the sides of sections on opposite sides of such section.

Preferably the screeds are secured to the underside of the flooring strips by a water-resistant adhesive such as of the ureaforlmaldehyde type or its equivalent. For ease of manufacture the `adhesive may be of the room temperature setting variety.

In the lpreferred construction of the ooring sections, the screeds are made of wood having a -thickness of 41/2 inch. In this respect, it has been found that 1/2 inch exterior type fir plywood or its equivalent is ideally suited for use in forming the screeds with a grade surface of B-C or better. The use of plywood for the screeds is preferred in that splitting is eliminated and plywood permits the flooring strips to separately shrink and swell with changes in humidity or moisture content.

For attaching the flooring sections to a supporting base such as a concrete slab, each of the end portions of the screeds projecting outwardly along one side of each section is provided with au aperture 40 to accommodate a suitable fastener F. To facilitate attachment of the ooring sections to the supporting base, particularly where such base is a concrete slab, power fasteners such as eX- plosively actuated fasteners may be employed. Thus, the commercially available Ramset fastener No. 3329 has been found to be suitable. These fasteners provide a 2 inch long shank of 1%4 inch diameter with a 3A; inch diameter head. The particular powder charge used with this fastener is contingent on the hardness of the concrete slab and can best be determined by test at the time of installation of a flooring structure. Alternatively, by

predrilli-ng the supporting base, Rawl drives or other manually applied fasteners may be used. Where this latter type of fastener is used a No. 12 Rawl drill is suitable for predrilling to accommodate 1A inch by 2 inch round head Rawl drive fasteners.

The ends of the screeds having the apertures 40 are preferably beveled as shown at 41. Such beveling of the screed ends facilitates assembly of the flooring sections, since after attachment of one section by fasteners engaged on apertures 4t), the next section may be readily moved into place with the projecting beveled screed ends passing beneath the side of the section being positioned.

Preferably the apertures 40 include -a counterbore 42 as shown more clearly in FIGURE 4, wherein the fastener F is shown engaged with aperture 40 and the head of such fastener received within counterbore 42. Where wood screeds are employed and power driven fasteners used in attaching the sections to the supporting base, it is considered desirable to provide a metal washer in the counterbore 42 to preclude undue penetration of the fastener through the screed.

As shown in FIGURE 3, the ends of the sections are beveled at 5ft so that the upper floor surfaces of adjoining sections will buttingly engage to provide a relatively smooth joint on the floor structure surface. The magnitude of this bevcliug is preferably between about 5 to 7.

In constructing the flooring sections the flooring strips are assembled with the tongues and grooves interengaged and clamped -to insure that the strips are perfectly at and in intimate contact. The butt joints between the ends of strips within the section will be staggered, as is characteristic of conventional strip flooring practice, with the butt joints tight. As previously mentioned, the longest possible strips shall be used along the outside edges in fabrication of the section. The sections will desirably be produced in two lengths, i.e., 4 feet and 8 feet, with a maximum length variation tolerance of 1,64 inch. The ends of the sections are cut perpendicular to the panel length, with the cut being beveled from top to bottomv (undercut) at an angle of about 5 to 7 as heretofore mentioned.

The screeds will be arranged and positioned on the underside of the clamped strips making up the section in accordance with the heretofore described relationship, and the screeds glued to the individual flooring strips making up the section.

To provide further support for the strip flooring between the screeds which are attached to the supporting base, there are preferably inserted filler strips 60. These filler strips extend longitudinally between the screeds and have a thickness substantially equal to the screed thickness, i.e. `1/2 inch or not over 1/64 inch less than 1/2 inch, so that they provide support between the base 10 and the strip'ooring of the sections. The tllerstrips may be formed from materials such as asphalt saturated cork, fiber insulation board or wood particle board. In an actual installation these filler strips may have a convenient length of between 2 feet and 8 feet. In positioning the iiller strips 60, preferably a mastic is employed such as of the cut back asphalt emulsion type. Such a mastic is applied to the supporting base where it is a concrete slab and also lapplied to the upper surface of the filler strips so that as the flooring sections are positioned, the tiller strips will be held in proper location. This mastic should be not over 1A; inch thick and the iller strips should be layed with a void or spacing of about 4 inches between adjacent parallel rows of filler strips. Further, a spacing or void of about l inch should be provided between the ends of adjoining filler strips in each row.

It will be readily recognized from the description given hereinabove that flooring sections may be assembled with ease and relativespeed into a complete floor structure. The construction steps for installing a iloor structure in accordance with the instant invention may be generally outlined as follows:

Where a new concrete slab is poured to provide the supporting base, it shall be trowelled or iloated to a true and level plane free of depressions, ridges or elevation. Sufficient heating and dry-ing of the sla-b shall be allowed to insure that it is free of moisture or wet spots. Where an existing concrete slab which is not level or contains depressions is used, it should be leveled by application thereto of a leveling course consisting of sand cement and mastic. Such leveling course should be allowed to dry at least forty-eight hours at la temperature of 65 F. to 70 F. prior to installation of the wood ooring structure.

After preparation of the supporting base, the filler strips are applied in mastic, not over 1/s inch thick, in straight parallel rows. As previously mentioned, 4 inch voids should be allowed between adjacent filler strip rows and a space or void of approximately l inch allowed between the ends of adjoining filler strips in each row. A second coating of mastic is applied to the surface of the filler strips prior to application of the flooring sections.

As shown in FIGURE l, a flooring section 11 is positioned at the corner of the supporting base to be lloored with the screeds entering the 4 inch spaces between adjacent filler strips. Suitable fasteners are driven through the apertures 40 in the screeds for such section to firmly attach such section to the supporting base. A group of flooring sections to form a complete row is then applied in this manner across the length dimension of the base. In starting the second row of flooring sections a section 12 will be positioned. at the beginning of such row so that all of the butt joints between the ends of adjoining sections will be staggered in relation to the joints between adjoining sections in the rst row.

The individual sections will be put in place by the projecting ends of their screeds being inserted beneath the sides of the sections which were previously fastened to the base in laying the preceding row. In the third row the initial section will be a section 11 so that again the joints between the ends of adjoining sections will be staggered with respect to joints in the second row. This procedure will be carried out in laying the flooring sections until the entire floor has been covered.

As previously mentioned, the flooring sections may be attached by suitable concrete fasteners of the power activated or manually driven type. In installing the flooring sections it is desirable to employ a fastener at each screed of all sections disposed within approximately 4 feet of either edge of the entire surface being oored. The use of fasteners at each screed along the edges of the surface being oored is important to provide requisite holding power or the sections against buckling caused by expansion occurring with increased moisture conditions. Also, at each screed of the sections disposed within approximately 21/2 feet on each side of the longitudinal center line of the surface being iloored, a fastener should be provided to retain such sections. The remaining portions of the iloor, not falling within the above defined zones, should be provided with one fastener at the two end andv center screeds of each 8 foot section and at the two end screeds of each 4 foot section.

It will be readily recognized that the flooring sections as described hereinabove may be easily cut at the site of installation, using conventional hand tools. In applying the flooring sections, they may be cut to conform to contours at vertical surfaces such as posts, columns, etc. In the event that cutting a section leaves unsupported ends of ooring strips extending more than 3 inches from the nearest screed, it is desirable that an auxiliary screed of preferably 1/2 inch plywood be laid on the supporting base against the vertical surface and secured to the base by appropriate fasteners. The free ends of the ooring strips which overlie this auxiliary screed may then be face-nailed to the auxiliary screed.

The face-nailing will generally be covered by suitable finished base molding.

In completing the flooring of a particular area, a space may remain along the edge of the surface to be oored less than the width of a liooring section. In such case, the sections to lill this narrow space may be rip-sawed to the requisite width and secured to the supporting base by inserting appropriate fasteners through predrilled and recessed holes in the face of the flooring strips. Alternatively, short auxiliary screeds may be installed as extensions of the screeds of previously laid flooring sections and the remaining narrow width space floored by using individual flooring strips applied by nailing in the conventional manner.

Since it is recognized that expansion and contraction of the ilooring sections will occur, desirably, expansion spaces at all ends and sides of the floored area of not less than 2 inches should be provided. These expansion spaces should not be filled with any material which would retard iioor movement.

The sectionalized floor structure, after installation, may be suitably finished by established oor-nishing techniques.

The sectionalized iloor structure of the instant invention permits easy repair and replacement of a damaged flooring section. Such repair may be effected by making parallel saw cuts close to the edge at each side of the damaged panel to a depth equal to the thickness of the flooring strips, plus the screed thickness or, in the example heretofore mentioned, to a depth of approximately 1%2. This will result in the wood screeds being cut close to the installed fasteners and the damaged panel can be lifted out of place. Care should be used in malting the saw cuts so as to not damage adjacent panels. The circular shape of the saw cuts will generally make it necessary to split the last few inches of the damaged floor section, using a chisel or other suitable tool.

Auxiliary new 1/2 inch screeds forming extensions of the screeds of adjacent flooring sections are then positioned in the area of the removed damaged section and these auxiliary screeds are secured to the supporting base by appropriate fasteners. Thereafter, conventional wood floor strips may be installed using nailing techniques common to standard flooring construction. The tongue of the last flooring strip to be installed can be removed and this strip face-nailed with the nails being countersunk and the recesses filled. In removing a damaged section, one of the adjacent sections will have the protruding screed ends containing the fasteners sawn through. The edge of this panel should be refastened by inserting appropriate fasteners through the face of the flooring strip along the loose panel edge, with such fasteners being countersunk and the recesses filled.

I claim:

A wood flooring structure comprising a plurality of elongated flooring sections rigidly connected to a supporting base to form a planar floor surface, said sections being rectangular with groups of such sections longitudinally aligned in end abutting relation to form rows of the sections longitudinally of the supporting base, each of said sections including a series of flooring strips with interengaged mating tongues and grooves providing a tongue extending along one side of the section and a fgroove extending along the opposite side of the section, a plurality of screeds glued to the underside of said strips extending transversely thereof at spaced positions along the length of the section, one of said screeds at one end of each section extending outwardly beyond the ends of the strips in such section, another of said screeds at the opposite end of each section being disposed inwardly of the ends of the strips in such section to leave the ends of the strips in such section extending freely beyond the outer edge of said another of said screeds, each of said screeds having end portions thereof projecting outwardly l@ beyond the opposite sides of the section and engaged faces of said ller strips retaining said filler strips posibeneath the sides of adjacent sections in the assembled tioned beneath said ooring strips. relation of said sections, the end portions of said screeds along one side of the section being provided with aper- References Cited m the me of dus Patent tures to accommodate fasteners for connecting said sec- 5 UNITED STATES PATENTS tions to the supporting base, ller strips disposed between 1,407,579 Ruthrauff Feb 21J 1922 adjacent screeds, said iler strips having a thickness sub- 2,257,219 Bath Sept 30, 1941 stantially equal to the thickness of said screeds providing 2,872,712 Brown Feb. 10, 1954 support for the segments of the ooring strips between FOREIGN PATENTS said screeds, and mastic material disposed on the opposite lo 172,149 Austria Jan. 15, 1952 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,026,578 March 27, 1962 Norvelle G. Hundley It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below In the grant, line 3, for "Dollar, Michigan" read Dollar Bay, Michigan in the heading to the' printed specification, lines 4 and 5, for "Dollar, Mich." read Dollar Bay, Mich.

Signed and sealed this 31st day of July 1962.

(SEAL) Attest:

ERNEST w. swlDER DAVID L- LADD Xttesting Officer Commissioner of Patents 

